The Auxx-Lift could be mounted on any ceiling (rafters/joists/sloped ceiling) THIS KIT IS OPTIONAL: Commonly the lift's motors run parallel for the ceiling joists. If you need the motors to operate perpendicular to your joists you may need this package. This extra kit will change the System ninety Levels This https://auxx-lift19754.wikiconverse.com/5587288/little_known_facts_about_auxx_lift_products